how to setup network and share folder for CentOS on virtualbox?

Hi I am beginner for linux. I installed CentOS for database on vritualbox running on windows 7. Network setting is set as NAT in virtualbox.

Question: 1. I want to linux is able to connect internet with the connection on windows 7. With other VM for windows, NAT will enable vm access internet automatically. but how to do it for linux?
2. I have download sybase ase for linux on windows 7. the file is ase157_linuxx86-64.tgz, how share this file for linux vm so that I can install it in linux?

1.) There should be an option for a "bridged" connection on your VM to link the internet connection from win 7 to the linux VM. I havent used virtualbox in a long time, but in VMWare the option is under "Edit virtual machine settings" >> Network Adapter

2.) Not really sure if this is possible to "share" folders between a home windows box and a VM of linux. I'll let others chime in on this one though who may have more experience. I've only made shared memory partitions for a dual-boot setup, but you have to understand Linux running in a VM is like running a completely different OS. You won't have access to the data on your win 7 OS. Probably setting something up via your network would work, but if you bridge the connection both your VM and your win7 box will have the same IP address i'd assume, which may cause troubles.

Really, all you need to do is download the software again through your Linux VM, not Win 7, and install it that way. Although I'm curious how you got a copy of Sybase ASE. I actually work as technical support for that product (Sybase is now SAP) and its proprietary and requires an enterprise-level license to use. If you found a "crack" for it or something similar I guess more power to you, but I think you'd be better off with something like mySQL if you aren't experienced with RDBMS software there are a LOT more tutorials on opensource options like mySQL than ASE.